In recent years, mobile phones and other data terminals have been made smaller and thinner. Along with this, to improve the portability, operability, and ease of viewing of the display, there are products which enable the display and other moving parts to slide with respect to the keyboard and other fixed parts. FIG. 1A illustrates a data terminal 3 in a state where a moving housing (upper side housing) 2 is superposed over a fixed housing (lower side housing) 1. This data terminal 3, as illustrated in FIG. 1B, is used in a state with the movable housing 2 made to slide with respect to the fixed housing 1. As such a form of a data terminal 3, for example, there are a mobile phone, mobile terminal (tablet computer or other small computer), game machine, etc.
In this regard, in such a data terminal 3, as illustrated in FIG. 1B, when making the movable housing 2 slide with respect to the fixed housing 1, due to the structure of the housing, an overlap part L was necessary between the fixed housing 1 and the movable housing 2 in the full open state (full slide state). For this reason, the amount of slide of the movable housing 2 with respect to the fixed housing 1 was only up to two-thirds of the housing length in the slide direction. This structure was fine in the case of making the lower side fixed housing 1 the keyboard, but when also making the lower side fixed housing 1 a display part, due to the overlap part L, it was not possible to obtain a sufficient area for display.
As opposed to this, as illustrated in FIG. 1C, a data terminal 4 of a structure where the movable housing 2 becomes flat (full flat) with respect to the fixed housing 1 at the time of full slide is, for example, disclosed in Japanese Laid-Open Publication No. 2009-71588 and Japanese Laid-Open Publication No. 2010-154149. In Japanese Laid-Open Publication No. 2009-71588, there is a connecting piece which connects the side surfaces of the fixed housing (first housing) and movable housing (second housing). One of two pins at the connecting piece is supported at the movable housing, while the other is slidably engaged with the fixed housing. Further, in Japanese Laid-Open Publication No. 2010-154149, the fixed housing (second housing) and the movable housing (first housing) are connected by a link mechanism. The movable housing is fully slid with respect to the fixed housing to make the display surface fully flat.
When using a mobile terminal for e-mails or Twitter® or other applications, a small size like that of a smart phone is sufficient, but when viewing an electronic magazine or newspaper, large screen size tablets are best suited. Further, it is hard to walk around while holding both a smart phone type mobile phone and a tablet, so there is a need for using a tablet for both purposes.
However, while there have been terminals where two screens have been made single flat screens up to now, there has never been a terminal which realizes the equivalent size as a tablet by connecting a larger number of screens, for example, four screens. Further, even if it had been possible to connect four housing sections to form a large screen data terminal, as illustrated in FIG. 1D, there was the issue of a step difference forming at the screens of the housing sections 5A to 5D divided into four so as to form a data terminal 5. Further, if a step difference arises, the screen becomes harder to view or a touch operation (wipe operation) ends up being obstructed. Furthermore, if the sizes of the four housing sections forming the four screens are matched with the thickest one, there is the problem that the thickness of the electronic device which is formed by superposing these increases and the apparatus becomes large in size.